Will Thermocol Ceiling Reduce Heat? (Analysis, Pros & Cons)

Last Updated on May 2, 2023 by Barry Gray

Living in a hot climate is made more bearable if you have a cool house to live in. It is incredibly frustrating to toss and perspire in your bed at night because of the heat. There are various approaches to cooling a house. You may choose to use an air conditioner, but this is expensive. Altering the structure and material in a ceiling can help reduce heat. One material commonly used is thermocol.

Thermocol ceilings reduce heat in rooms as they are poor heat conductors. The structure of polystyrene allows gas to be trapped between the molecules. This gives it low thermal conductivity and prevents heat transference. Thermocol ceilings can reduce the indoor temperature by five degrees.  

If you are building a new house or upgrading the insulation on your current home, thermocol ceiling is worth investigating. 

Does Thermocol Help Keep A House Cool?

Thermocol has been used for many years to make ceilings. The main aim of using thermocol is as an insulator. It protects against heat entering the building during summer and loss of heat during winter.   

Thermocol ceiling boards are manufactured in different widths. Thicker thermocol boards will result in better insulation and heat reduction. Most energy specialists aim to reduce the house temperature by five degrees when using thermocol. 

How Does Thermocol Reduce Heat?

To understand how thermocol reduces heat, we need to know how it is formed. Styrene is a liquid hydrocarbon by-product of petroleum. It goes through a process of polymerization and becomes polystyrene beads. 

These beads are steamed and heated to very high temperatures. They expand and fuse to form a honeycomb structured material called stretch polystyrene or thermocol. The expansion of the beads results in air being trapped in the material. Thermocol is made up of 95 % air and 5 % polystyrene.

Air, like most gases, is not a good thermal conductor. The many spaces filled with air in thermocol do not allow heat to be transmitted through the material. Thermocol is described as having a low thermal mass. This means that it does not absorb or retain heat.

How Is Thermocol Used In Buildings?

The roof of a structure is the surface exposed to the most solar radiation. As a result, the roof heats up considerably during the day, especially in summer. 

Heat energy always moves from a high heat area to a cooler region. This is achieved through convection currents in the air or by heat conduction through adjacent materials. The heat of the roof is transferred into the cooler house below. 

There must be an insulating material to prevent the transference of heat energy from the roof. Thermocol is a good insulator due to the air spaces in its structure. 

Thermocol may be used to construct the ceiling in houses. Thermocol ceiling boards replace traditional ceiling boards in an effort to cool the home. Thermocol panels are light and easy to install. 

More often, though, false ceilings are constructed from thermocol. False ceilings are suspended below the ceiling allowing a void which further reduces heat movement from the roof to the house. Any heat that crosses the space is prevented from moving further due to the poor heat conduction of thermocol. 

In some countries, thermocol boards are used as an insulation layer between the ceiling and the roof.

What Are The Advantages Of Thermocol Ceilings?

  1. Thermocol ceilings reduce heat transference from solar-heated roofs during summer. They, therefore, cool the building down by several degrees.  
  1. Thermocol ceilings prevent heat from being lost from the home through the roof during winter.
  1. Thermocol is a light material due to all the air spaces in its composition. This feature makes it easy to install. Its minimal weight does not put undue stress on building structures. 
  1. It is cheap and can reduce building costs. Installation can be done with fewer labor costs due to its light weight and ease of installation. Thermocol is popular with construction teams as it does not shed irritating fiberglass fibers or dust as some other ceiling boards do.
  1. Thermocol ceilings reduce energy expenses as air conditioners and heaters are used less in the summer and winter months, respectively.
  1. Thermocol ceiling boards can be shaped, carved, and designed to produce aesthetically pleasing ceilings. Panels may also be bought with pre-molded designs pressed into them. 
  1. Thermocol ceiling hides unsightly wiring and plumbing pipes.
  1. Thermocol can be painted. It is generally sold as white panels, but it is possible to buy colored thermocol ceiling boards.
  1. Thermocol is an inorganic material that does not absorb water. This makes it resistant to mold and fungal spores.
  1. Thermocol boards can be easily cleaned if they get dirty.
  1. Thermocol ceiling boards are designed to last for several decades. Some boards may come with a thirty to fifty-year warranty.

What Are The Disadvantages Of Thermocol Ceilings?

  1. Thermocol ceilings are extremely flammable, burning with thick black smoke. Some modern products have a fire retardant additive to increase safety in case of fire.
  1. Thermocol gives off poisonous gases when burning. The gases can cause respiratory difficulties and even death. The fumes are carcinogenic, and exposure to them can have lasting consequences. 
  1. Thermocol false ceilings prevent you from seeing water leaks, damp, mold, or other problems on the ceiling. This results in issues escalating in severity before they are noticed.
  1. Thermocol is not biodegradable and is harmful to the environment. It has become a significant source of environmental pollution. 
  1. Care must be taken when installing recessed lights or downlights. The heat from these lights can result in the thermocol shrinking or shriveling around the lights. It is best to use a heat insulator, such as aluminum, around the light fitting. Alternatively, energy-efficient lights can be used as they produce less heat. 


Thermocol ceilings reduce heat in buildings through the structural composition of the material, which retards heat transference. Thermocol boards are often used as false or suspended ceilings, further reducing heat in a home. There are advantages and disadvantages to using thermocol for ceilings, and these must be taken into consideration. Environmental concerns are a significant factor when considering thermocol for ceilings.

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Barry Gray

Hi, I’m Barry. I’ve loved woodworking and bringing things back to life for more years than I care to remember. I hope my passion for tools comes across loud and clear in everything you read here on The Tool Square.